/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.thrift.transport;

/**
 * Server transport. Object which provides client transports.
 * 
 */
public abstract class TServerTransport {

	protected TServerTransportAcceptFilter acceptFilter;

	public TServerTransportAcceptFilter getAcceptFilter() {
		return acceptFilter;
	}

	public void setAcceptFilter(TServerTransportAcceptFilter acceptFilter) {
		this.acceptFilter = acceptFilter;
	}

	public abstract void listen() throws TTransportException;

	public final TTransport accept() throws TTransportException {
		TTransport transport = acceptImpl();
		if (transport == null) {
			throw new TTransportException("accept() may not return NULL");
		}
		if (this.acceptFilter != null) {
			TTransport nt = this.acceptFilter.filter(transport);
			if (nt == null) {
				try {
					transport.close();
				} catch (Exception e) {
				}
				throw new TTransportException(transport + " filter fail");
			}
			transport = nt;
		}
		return transport;
	}

	public abstract void close();

	protected abstract TTransport acceptImpl() throws TTransportException;

	/**
	 * Optional method implementation. This signals to the server transport that
	 * it should break out of any accept() or listen() that it is currently
	 * blocked on. This method, if implemented, MUST be thread safe, as it may
	 * be called from a different thread context than the other TServerTransport
	 * methods.
	 */
	public void interrupt() {
	}

}
